JP6770849B2 - Work platform - Google Patents

Description

The present invention has an input rotating body, an output rotating body, and a drive belt wound around the input rotating body and the output rotating body, and continuously changes the power from the engine and transmits the power to the traveling device. It relates to a work vehicle equipped with a belt-type continuously variable transmission mechanism.

The conventional work platform is shown in, for example, Patent Document 1 below. After a certain amount of use of the belt-type continuously variable transmission mechanism, the wear of components such as the drive belt progresses, so maintenance such as replacement of parts is required.

Japanese Unexamined Patent Publication No. 2012-51505

In the conventional technology, in order to determine whether or not maintenance of the belt-type continuously variable transmission mechanism is necessary, it is necessary to disassemble the belt-type continuously variable transmission mechanism and measure the state of the drive belt. It was common. However, such work is very time-consuming and requires skill in measurement, so that it has not been easily performed by the operator or the like as a user.
In addition, since the degree of wear of components such as the drive belt in the belt-type continuously variable transmission mechanism largely depends on the usage conditions, the timing for maintenance of the belt-type continuously variable transmission mechanism should be unequivocally determined only during the period of use. Was difficult.
For this reason, it has been difficult for the operator or the like to easily grasp the appropriate timing for performing maintenance of the belt-type continuously variable transmission mechanism.

In view of the above circumstances, it has been desired to provide a work vehicle that allows the operator or the like to easily grasp the appropriate timing for performing maintenance of the belt-type continuously variable transmission mechanism.

The work platform of the present invention
A belt having an input rotating body, an output rotating body, the input rotating body, and a drive belt wound around the output rotating body, and continuously shifting the power from the engine to the traveling device. With a continuously variable transmission mechanism
A rotation detector that detects the engine speed and
A vehicle speed detector that detects the vehicle speed of the traveling aircraft,
When the vehicle speed detected by the vehicle speed detection unit is a predetermined vehicle speed and the engine speed detected by the rotation detection unit deviates from a preset allowable range, a warning notification is given to warn the wear of the drive belt. When a notification unit is provided , the predetermined vehicle speed is a preset maximum vehicle speed as a vehicle speed for suppressing the rotation of the engine, and the vehicle speed detected by the vehicle speed detection unit is the limited maximum vehicle speed. Only, when the engine speed at the limited maximum vehicle speed exceeds a predetermined threshold value, the notification unit gives the warning notification .

As the wear of the drive belt in the belt-type continuously variable transmission mechanism progresses, the belt width becomes smaller than in the non-weared state, and the winding diameter of the drive belt in each of the input rotating body and the output rotating body changes. There is a tendency for the power transmission efficiency to decrease due to slippage of the drive belt or the like. As a result, as the wear of the drive belt progresses, the gear ratio of the belt-type continuously variable transmission mechanism changes, and the relationship between the engine speed on the input side and the vehicle speed, which is the final output result, also changes. ..
In the present invention, in order to utilize the change caused by the progress of wear of the drive belt of the belt-type continuously variable transmission mechanism as described above, the drive of the belt-type continuously variable transmission mechanism is performed with respect to the engine speed when the vehicle speed is a predetermined vehicle speed. The permissible range in consideration of belt wear is set in advance. Then, during actual driving, if the engine speed detected when the vehicle speed is a predetermined vehicle speed deviates from the set allowable range, the drive belt of the drive belt requires maintenance for the belt-type continuously variable transmission mechanism. It is determined that wear is progressing, and a warning notification is given to warn the wear of the drive belt to alert the operator and the like. Therefore, the operator or the like can easily grasp that the maintenance of the belt-type continuously variable transmission mechanism is necessary without taking the trouble of disassembling the belt-type continuously variable transmission mechanism, and the drive belt is excessively worn. It is also possible to avoid the continuation of use in the state of progress.
As described above, according to the present invention, the operator or the like can easily grasp the appropriate timing for performing maintenance of the belt-type continuously variable transmission mechanism.

Further , according to the present invention , when the vehicle speed reaches the preset maximum vehicle speed, the belt-type continuously variable transmission mechanism is in a specific shift state. Therefore, for example, the shift state of the belt-type continuously variable transmission mechanism is changed. It is possible to compare the engine speeds with higher accuracy than to compare the engine speeds in the vehicle speed range that changes steplessly. In addition, when the gear ratio of the belt-type continuously variable transmission increases as the drive belt wears, the engine speed detected when it is detected that the vehicle speed is the maximum vehicle speed limit is determined. By using the presence or absence of exceeding a predetermined threshold value as a reference, it is possible to suitably determine the wear of the drive belt, and it is possible to give a warning notification to the operator or the like at an appropriate timing.

In the present invention
It is preferable that the threshold value is the engine speed at which the limited maximum vehicle speed is achieved in the belt-type continuously variable transmission mechanism having the drive belt in a predetermined wear state.

According to this configuration, an actual machine equipped with a belt-type continuously variable transmission mechanism having a drive belt in a predetermined wear state is tested, and the engine speed is compared with the engine speed at the maximum vehicle speed limit based on the test run result of the actual machine. The threshold value to be set is set. In this way, by using the data of the actual machine when setting the threshold value, for example, it is possible to set the threshold value with an appropriate value as compared with the case of setting the threshold value based on the simulation data. A warning can be given at the timing when the wear has progressed as expected.

In the present invention
It is preferable that the notification unit performs a preliminary notification different from the warning notification when the engine speed exceeds a preliminary value smaller than the threshold value.

According to this configuration, the operator or the like can belt type by notifying the operator or the like by preliminary notification that the wear of the drive belt has progressed to some extent before issuing the warning notification to warn the wear of the drive belt. It becomes easier to predict when to perform maintenance on the continuously variable transmission mechanism.

In the present invention
When the engine speed becomes equal to or higher than the limit speed set based on the threshold value, it is preferable that the engine speed is suppressed even if the vehicle speed does not reach the limit maximum vehicle speed. is there.

According to this configuration, when the drive belt of the belt-type continuously variable transmission mechanism wears and the detected engine speed exceeds the limit speed, the engine speed does not matter regardless of the detected vehicle speed. It is designed to suppress the increase in numbers. As a result, the engine is less likely to fall into an overspeed state, the engine can be protected from damage, and an undesired phenomenon such as a sudden increase in the amount of soot contained in the exhaust gas due to poor combustion of the engine can be avoided. ..

It is a top view which shows the whole of a multipurpose vehicle. It is a partial cross-sectional view of the top view which shows the structure of a belt type continuously variable transmission mechanism. It is a block diagram which shows an example of a control structure and a power transmission structure. It is a flowchart which shows an example of the flow of performing preliminary notification and warning notification. It is a flowchart which shows an example of the flow at the time of suppressing the engine speed. It is a figure which shows an example of the relationship between the engine speed and a vehicle speed in another embodiment.

Hereinafter, embodiments that are an example of the present invention will be described with reference to the drawings.
Regarding the direction, the direction of the arrow F shown in FIG. 1 is "front", the direction of the arrow B is "rear", the direction of the arrow L is "left", and the direction of the arrow R is "right".

The multipurpose vehicle (an example of a “working vehicle”) shown in FIG. 1 is a vehicle that can be used for various purposes such as carrying loads and recreation.
As shown in FIG. 1, the multipurpose vehicle includes a traveling body capable of self-propelling by a traveling device T composed of a pair of left and right front wheels 1 that can be steered and driven and a pair of left and right rear wheels 2 that can be driven. It is equipped. A driving unit 3 on which passengers board is provided at the center of the front and rear of the traveling aircraft.
The rear part of the driving unit 3 of the traveling machine body is provided with a loading platform 4 capable of loading a load and dumping the load in a backward leaning posture to discharge the load. Below the loading platform 4 of the traveling machine body, a gasoline engine as a power source (hereinafter, simply referred to as "engine 5") and a transmission 6 capable of shifting the power of the engine 5 are provided.

As shown in FIG. 1, the driver unit 3 includes a driver's seat 7 in which the driver can sit, an auxiliary seat 8 in which the passenger can sit, a steering wheel 9 for steering operation, and a shift for shifting. As an operation input tool for commanding the target engine speed and changing the vehicle speed with respect to the lever 10 and the engine 5, the accelerator pedal 11, the brake pedal 12 capable of braking operation, and a display device capable of displaying various information. The meter panel 13 and the buzzer device 14 as a sound generating device for generating a sound are provided. The boarding space in which the passengers board in the driver unit 3 is protected by being surrounded by a protective frame 15 formed by combining frame bodies.

As shown in FIGS. 1 to 3, the transmission 6 is provided with a continuously variable transmission type belt type continuously variable transmission mechanism 16, a stepless speed change type gear type transmission mechanism 17, and the like. The power of the engine 5 is transmitted to the traveling device T after receiving a predetermined shift by the belt-type continuously variable transmission mechanism 16 and further receiving a predetermined shift by the gear-type continuously variable transmission mechanism 17. The belt-type continuously variable transmission mechanism 16 is housed in a speed change case 18 located on the lateral side of the engine 5. The gear type transmission mechanism 17 is housed in a mission case 19 located on the rear side of the engine 5.

[About the belt-type continuously variable transmission]
As shown in FIGS. 2 and 3, the belt-type continuously variable transmission mechanism 16 continuously shifts the power from the engine 5 and transmits the power to the traveling device T. As shown in FIG. 2, the belt-type stepless speed change mechanism 16 includes a speed change input shaft 21 that can be connected to the output shaft 20 of the engine 5, an input rotating body 22 as a drive pulley that rotates integrally with the speed change input shaft 21. A shift output shaft 23 that is arranged parallel to the shift input shaft 21 and outputs power to the gear type transmission mechanism 17, an output rotating body 24 as a driven pulley that integrally rotates the shifting output shaft 23, and an input rotating body 22 and output rotation. A drive belt 25 having a V-shaped cross section, which is a rubber endless rotating body that is wound and stretched over the body 24, and the winding diameter and winding diameter of the drive belt 25 in the input rotating body 22 according to the engine rotation speed. It has a winding diameter adjusting mechanism 26 capable of changing the winding diameter of the drive belt 25 in the output rotating body 24.

As can be understood from FIG. 2, the connection between the output shaft 20 of the engine 5 and the speed change input shaft 21 of the belt-type continuously variable transmission mechanism 16 is released or connected by the centrifugal clutch 27. When the rotation speed (engine rotation speed) of the output shaft 20 of the engine 5 per unit time is less than the set value (for example, idling rotation speed), the centrifugal clutch 27 is in the disconnected state and the output of the engine 5 is output. The connection between the shaft 20 and the speed change input shaft 21 of the belt-type stepless speed change mechanism 16 is released, and power is not transmitted to the speed change input shaft 21. On the other hand, when the engine speed is equal to or higher than the set value, the centrifugal clutch 27 is in a connected state, and the output shaft 20 of the engine 5 and the speed change input shaft 21 of the belt-type stepless speed change mechanism 16 are connected and integrated. The power of the engine 5 is transmitted to the shift input shaft 21 in a rotating state.

As shown in FIG. 2, the input rotating body 22 is integrally rotated with the shift input shaft 21 and is integrally rotated with the drive side fixed sheave 28 which is immovable in the axial direction of the shift input shaft 21 and the shift input shaft 21. A drive-side movable sheave 29 that can move in the axial direction of the shift input shaft 21 is provided. When the drive belt 25 is sandwiched between the drive-side fixed sheave 28 and the drive-side movable sheave 29 and the distance between the drive-side fixed sheave 28 and the drive-side movable sheave 29 changes, the drive belt 25 in the input rotating body 22 The winding diameter of is changed.

The output rotating body 24 includes a driven side fixed sheave 30 that rotates integrally with the shift output shaft 23 and cannot move in the axial direction of the shift output shaft 23, and a shift output shaft 23 that rotates integrally with the shift output shaft 23 in the axial direction. A driven side movable sheave 31 that can be moved to and is provided. When the drive belt 25 is sandwiched between the driven side fixed sheave 30 and the driven side movable sheave 31 and the distance between the driven side fixed sheave 30 and the driven side movable sheave 31 changes, the drive belt 25 in the output rotating body 24 The winding diameter of is changed.

The winding diameter adjusting mechanism 26 includes a weight roller 32 that rotates integrally with the speed change input shaft 21, and a center spring 33 that rotates integrally with the speed change output shaft 23. The weight roller 32 is adapted to generate a force for pressing the drive-side movable sheave 29 toward the drive-side fixed sheave 28 by centrifugal force as the shift input shaft 21 rotates. The pressing force by the weight roller 32 becomes stronger as the engine speed (the speed of the shift input shaft 21) increases. The center spring 33 applies an urging force to the driven side movable sheave 31 to press the driven side movable sheave 31 toward the driven side fixed sheave 30.

The belt-type continuously variable transmission mechanism 16 configured as described above has the urging force of the center spring 33 when the engine speed (the number of revolutions of the shift input shaft 21) is less than the set value and the driving force is not transmitted. As a result, the winding diameter of the drive belt 25 on the input rotating body 22 is the minimum, and the winding diameter of the drive belt 25 on the output rotating body 24 is the maximum, so that the gear ratio is the maximum. Then, in the belt-type continuously variable transmission mechanism 16, as the engine speed is increased from a value equal to or higher than the set value, the pressing force by the weight roller 32 that opposes the urging force of the center spring 33 becomes stronger, and the drive belt 25 rotates at the input. By sliding the inclined contact surfaces of the body 22 and the output rotating body 24, the winding diameter of the drive belt 25 in the input rotating body 22 becomes large, and the winding diameter of the drive belt 25 in the output rotating body 24 becomes small. Then, the gear ratio changes steplessly and becomes smaller. In the belt-type continuously variable transmission mechanism 16, when the engine speed exceeds a predetermined value larger than the set value, the winding diameter of the drive belt 25 on the input rotating body 22 is maximum, and the drive belt 25 on the output rotating body 24 A specific shift state is obtained in which the winding diameter is minimized and the gear ratio is minimized. When the engine speed is reduced from a predetermined value, the operation opposite to the above is performed.

As shown in FIG. 2, a cooling fan 34 that rotates integrally with the shift output shaft 23 is provided on the free end side of the shift output shaft 23. Wind is generated by the cooling fan 34 due to the rotational drive of the speed change output shaft 23, the air in the speed change case 18 is agitated, and the cooling air is taken in from the intake port 35 of the speed change case 18, and the plurality of outlets 36 The cooled air is discharged from the drive belt 25 to cool the drive belt 25 and the like, and the progress of wear of the drive belt 25 due to frictional heat is alleviated.

[About gear type transmission mechanism]
As shown in FIGS. 1 and 3, the gear type transmission mechanism 17 can perform stepwise speed change and output the power input from the shift output shaft 23 of the belt type continuously variable transmission mechanism 16 toward the traveling device T. ing.
As can be understood from FIG. 3, when the speed change lever 10 is operated to the reverse position RP, the gear type transmission mechanism 17 is in a reverse state in which the reverse power is transmitted to the traveling device T. Further, when the shift lever 10 is operated to the neutral position NP, the gear type transmission mechanism 17 is in a neutral state in which the driving force is not transmitted to the traveling device T. Further, when the gear type transmission mechanism 17 operates the shift lever 10 to the forward low speed position LP, the gear type transmission mechanism 17 enters a forward low speed state in which the forward low speed power is transmitted to the traveling device T. Further, when the gear type speed change mechanism 17 operates the speed change lever 10 to the forward high speed position HP, the gear type transmission mechanism 17 enters a forward high speed state in which the forward high speed power is transmitted to the traveling device T.

As shown in FIG. 1, the power output from the gear type transmission mechanism 17 is transmitted to the left and right rear wheels 2. Further, the power output from the gear type transmission mechanism 17 can be transmitted to the left and right front wheels 1 via the power take-out shaft 37 extending forward and the propulsion shaft 38 extending in the front-rear direction. In this multipurpose vehicle, it is possible to switch between a two-wheel drive state and a four-wheel drive state. When the transmission clutch (not shown) of the gear type transmission mechanism 17 is disengaged, power is not transmitted to the propulsion shaft 38, the left and right front wheels 1 are not driven, and only the left and right rear wheels 2 are driven. It becomes a two-wheel drive state. On the other hand, when the transmission clutch of the gear type transmission mechanism 17 is engaged, power is transmitted to the propulsion shaft 38, and the left and right front wheels 1 and the left and right rear wheels 2 are driven into a four-wheel drive state.

[Wear of drive belt of belt type continuously variable transmission mechanism]
When the drive belt 25 of the belt-type continuously variable transmission mechanism 16 shown in FIGS. 2 and 3 is worn, the belt width of the drive belt 25 becomes smaller and the gear ratio becomes smaller than when the drive belt 25 is not worn. Change. In the present embodiment, the belt-type continuously variable transmission mechanism 16 in which the drive belt 25 is worn has a larger gear ratio (shifts to the deceleration side) and realizes the same vehicle speed as compared with the case where the drive belt 25 is not worn. The engine speed for this is increased.

[Control configuration]
As shown in FIG. 3, the multipurpose vehicle is provided with a control device 40 that controls the engine 5 and the notification. The control device 40 includes a rotation detection unit 42 that detects the engine speed based on the signal of the engine rotation sensor 41, a vehicle speed detection unit 44 that detects the vehicle speed of the traveling vehicle based on the signal of the vehicle speed sensor 43, and the engine 5. The engine control unit 45 for controlling the above, the determination unit 46 for performing various determinations, and the notification unit 47 for performing various notifications are provided.

When the amount of depression of the accelerator pedal 11 is zero, the engine control unit 45 adjusts the fuel injection amount and the ignition frequency with respect to the engine 5 and controls the engine 5 so that the engine speed becomes less than the set value. Further, the engine control unit 45 basically controls the engine 5 so as to increase the fuel injection amount and the ignition frequency with respect to the engine 5 and increase the engine speed according to the amount of depression of the accelerator pedal 11. On the other hand, when the vehicle speed detected by the vehicle speed detection unit 44 exceeds the limit maximum vehicle speed VMAX preset based on the specifications, the engine control unit 45 ignores the depression amount of the accelerator pedal 11 and increases the vehicle speed. The engine 5 is controlled so as to suppress the fuel injection amount and the ignition frequency with respect to the engine 5 so as to suppress the engine speed.

The maximum vehicle speed limit VMAX is set to a value smaller than the upper limit vehicle speed realized when the performance of the engine 5 is exerted to the mechanical limit. Further, when the vehicle speed reaches the maximum vehicle speed VMAX, the gear type transmission mechanism 17 is in the forward high speed state (the state in which the shift lever 10 is in the forward high speed position HP), and the belt type continuously variable transmission mechanism 16 is in a forward high speed position HP. It is in a specific shifting state where the gear ratio is minimized.

The determination unit 46 makes a determination to control the engine 5 and control various notifications. Specifically, the determination unit 46 determines whether or not the vehicle speed detected by the vehicle speed detection unit 44 is a predetermined vehicle speed. Further, the determination unit 46 determines whether or not the vehicle speed detected by the vehicle speed detection unit 44 is out of the preset allowable range C for the engine speed detected by the rotation detection unit 42 when the vehicle speed is a predetermined vehicle speed. judge. In the present embodiment, the predetermined vehicle speed is a limited maximum vehicle speed VMAX preset as a vehicle speed for suppressing the rotation of the engine 5.

Further, the determination unit 46 determines whether or not the engine speed exceeds a predetermined threshold value A2 when the vehicle speed detected by the vehicle speed detection unit 44 is the limited maximum vehicle speed VMAX. In the present embodiment, the threshold value A2 is the same value as the upper limit value of the allowable range C for the engine speed.

Further, the determination unit 46 determines whether or not the engine speed when the vehicle speed detected by the vehicle speed detection unit 44 is the limited maximum vehicle speed VMAX exceeds the preliminary value A1 which is smaller than the threshold value A2. ..

FIG. 3 shows an example of non-wear data D1 showing the relationship between the engine speed and the vehicle speed of a multipurpose vehicle equipped with a belt-type continuously variable transmission mechanism 16 having a new (non-weared) drive belt 25. ing. As the wear of the drive belt 25 progresses, the engine speed when the vehicle speed is the limited maximum vehicle speed VMAX is approaching the threshold value A2.

The permissible range C, the threshold value A2, and the preliminary value A1, which are compared with the engine speed when the vehicle speed detected by the vehicle speed detection unit 44 is a predetermined vehicle speed, are belts having a drive belt 25 in a predetermined wear state, respectively. It is set based on the relationship between the vehicle speed and the engine speed when the actual machine of the multipurpose vehicle equipped with the continuously variable transmission mechanism 16 is tested, and is stored in the determination unit 46. That is, the threshold value A2 is the engine speed at which the limited maximum vehicle speed VMAX is achieved in the belt-type continuously variable transmission mechanism 16 having the drive belt 25 in a predetermined wear state.

[Preliminary notification and warning notification]
As shown in FIGS. 3 and 4, the notification unit 47 notifies the preliminary notification B1 or the warning notification according to the determination result of the determination unit 46, for example, by displaying information by the meter panel 13 or generating a sound by the buzzer device 14. It is designed to perform B2. In the present embodiment, the determination process for the preliminary notification B1 or the warning notification B2 (step # a02, step) only when the vehicle speed is the limited maximum vehicle speed VMAX that suppresses the engine speed (step # a01: YES). # A04) is to be performed.

Specifically, as shown in FIG. 4 and the like, the belt type continuously variable transmission is performed in a state where the vehicle speed detected by the vehicle speed detection unit 44 is at a predetermined vehicle speed (limit maximum vehicle speed VMAX) (step # a01: YES). When the determination unit 46 determines that the drive belt 25 of the transmission mechanism 16 is worn to some extent and the engine speed detected by the rotation detection unit 42 exceeds the preliminary value A1 (step # a02). : YES), preliminary notification B1 is performed (step # a03). In this case, the engine speed detected by the rotation detection unit 42 does not exceed the threshold value A2.

In the next stage after a certain period of use, as shown in FIG. 4 and the like, the vehicle speed detected by the vehicle speed detection unit 44 is in a predetermined vehicle speed (limited maximum vehicle speed VMAX) (step # a01: YES). When the drive belt 25 of the belt-type continuously variable transmission 16 is considerably worn, and the determination unit 46 determines that the engine speed detected by the rotation detection unit 42 is out of the permissible range C. (Step # a04: YES), warning notification B2 is performed (step # a05). In other words, the engine speed detected by the rotation detection unit 42 is the threshold value A2 while the vehicle speed detected by the vehicle speed detection unit 44 is at the predetermined vehicle speed (limit maximum vehicle speed VMAX) (step # a01: YES). If it is determined that the value exceeds (step # a04: YES), the warning notification B2 is performed (step # a05).

That is, the notification unit 47 wears the drive belt 25 when the engine speed detected by the rotation detection unit 42 when the vehicle speed detected by the vehicle speed detection unit 44 is out of the preset allowable range C. Warning notification B2 is performed to warn. In other words, the notification unit 47 is a limited maximum vehicle speed VMAX in which a predetermined vehicle speed is preset as a vehicle speed for suppressing the rotation of the engine 5, and when the engine rotation speed at the limited maximum vehicle speed VMAX exceeds a predetermined threshold value A2, Warning notification B2 is performed. In this case, the predetermined vehicle speed is the limited maximum vehicle speed VMAX set in the specifications as described above. The maximum vehicle speed limit VMAX is set smaller than the limit vehicle speed, which is the mechanical limit. Further, the notification unit 47 performs a preliminary notification B1 different from the warning notification B2 when the engine speed exceeds the preliminary value A1 which is smaller than the threshold value A2.

In this way, by automatically detecting the degree of wear of the drive belt 25 of the belt-type continuously variable transmission mechanism 16 and performing preliminary notification B1 and warning notification B2, the passenger (operator or passenger) can perform. , The appropriate timing for performing maintenance of the belt-type continuously variable transmission mechanism 16 can be easily grasped.
Therefore, it is not necessary to disassemble the belt-type continuously variable transmission mechanism 16 in order to determine whether or not maintenance is required for the belt-type continuously variable transmission mechanism 16, and a warning is given before the drive belt 25 is damaged. Early maintenance can be promoted by the notification B2.

[About suppressing engine speed]
As shown in FIG. 5, when the engine speed becomes equal to or higher than the limit speed RMAX preset based on the specifications (step # b01: YES), the engine control unit 45 uses the vehicle speed detection unit 44. Regardless of the magnitude of the detected vehicle speed, the fuel injection amount to the engine 5 is forcibly suppressed (the fuel injection amount is reduced to zero or the fuel injection amount is reduced), and the ignition of the engine 5 is suppressed. (Prevent ignition or reduce the ignition frequency) and suppress the engine speed (step # b02). That is, when the engine speed detected by the rotation detection unit 42 exceeds the limit speed RMAX set based on the threshold value A2, the engine control unit 45 uses the engine even if the vehicle speed does not reach the limit maximum vehicle speed VMAX. It is configured to suppress the number of revolutions. As a result, the engine control unit 45 controls the engine 5 so that the engine speed does not rise above the limit speed RMAX. The limit rotation speed RMAX is set to a value smaller than the limit rotation speed which is the mechanical limit.

The limit rotation speed RMAX is set to a value smaller than the upper limit rotation speed which is the mechanical limit of the engine 5. In the present embodiment, the limit rotation speed RMAX is the same value as the threshold value A2 for performing the warning notification B2.

In this way, since the engine speed is prevented from becoming excessive, it is possible to prevent an undesired phenomenon such as valve surging or valve bounce from occurring in the engine 5 or an excessive load on the drive system. Further, it is possible to avoid the inconvenience that the engine 5 deviates from the ideal air-fuel ratio and a large amount of soot such as exhaust particles is mixed in the exhaust gas from the engine 5.

[Another Embodiment]
Hereinafter, another embodiment of the present invention will be described. Each of the following embodiments can be selected and applied to the above embodiments as long as there is no contradiction. The scope of the present invention is not limited to the contents of these embodiments.

(1) In the above embodiment, the engine speed detected by the rotation detection unit 42 is set to an allowable range C, a threshold value A2, and a preliminary value only when the vehicle speed detected by the vehicle speed detection unit 44 is the limited maximum vehicle speed VMAX. An example is shown in which the preliminary notification B1 and the warning notification B2 are performed in comparison with A1, but the present invention is not limited to this. For example, as shown in FIG. 6, the wear data D2 recorded by mapping the relationship between the vehicle speed and the engine speed of the belt-type continuously variable transmission mechanism 16 in a state where the drive belt 25 is worn is stored in the determination unit 46. Then, the allowable range C, the preliminary value A1, and the threshold value A2 may be set based on the wear data M1. Then, the detection data M2 is compared with the permissible range C, the threshold value A2, and the preliminary value A1, and the preliminary notification B1 and the warning notification B2 are performed. In this case, the preliminary value A1 and the threshold value A2 can be set in a wide range of vehicle speeds. That is, in this case, the predetermined vehicle speed for performing the determination process for the preliminary notification B1 or the warning notification B2 is not limited to the limited maximum vehicle speed VMAX, and is within the vehicle speed range in which the preliminary value A1 and the threshold value A2 are set. It can be any vehicle speed.

(2) In the above embodiment, the threshold value A2 is the same as the upper limit value of the allowable range C for the engine speed, but the present invention is not limited to this. For example, the threshold value A2 may be the same value as the lower limit value of the allowable range C for the engine speed. In this case, when the drive belt 25 is worn, the gear ratio becomes smaller, and the engine speed for achieving the same vehicle speed becomes smaller, which is another belt-type continuously variable transmission mechanism. Further, the threshold value A2 may be a value outside the permissible range C for the engine speed.

(3) In the above embodiment, the threshold value A2 has the same value as the limit rotation speed RMAX, but the present invention is not limited to this. The threshold value A2 may have a value different from the limit rotation speed RMAX.

(4) In the above embodiment, only one preliminary value A1 is set, but the present invention is not limited to this. For example, a plurality of preliminary values A1 may be set. As a result, as the wear of the drive belt 25 of the belt-type continuously variable transmission mechanism 16 progresses, the preliminary notification B1 is performed in a plurality of stages.

(5) In the above embodiment, the predetermined vehicle speed is exemplified as the limited maximum vehicle speed VMAX preset as the vehicle speed for suppressing the rotation of the engine 5, but the present invention is not limited to this. For example, the predetermined vehicle speed may be set to a value smaller than the limit maximum vehicle speed VMAX preset as the vehicle speed for suppressing the rotation of the engine 5.

(6) In the above embodiment, when an actual machine equipped with a belt-type continuously variable transmission mechanism 16 having a drive belt 25 in a predetermined wear state is tested and the maximum vehicle speed is limited to VMAX based on the test run result of the actual machine. An example is shown in which a threshold value A2 or the like to be compared with the engine speed is set, but the present invention is not limited to this. The threshold value A2 and the like may be set based on the simulation data instead of the test run data of the actual machine.

(7) In the above embodiment, the meter panel 13 is exemplified as the display device, and the buzzer device 14 is exemplified as the sound generator, but the present invention is not limited to this. Various devices can be adopted as the display device and the sound generator. Further, when performing the preliminary notification B1 and the warning notification B2, the notification may be performed by both the display device and the sound generator, or the notification may be performed by only one of the display device and the sound generator. It may be.

(8) In the above embodiment, when the engine speed becomes equal to or higher than the limit speed RMAX, the fuel injection amount to the engine 5 is suppressed and the ignition of the engine 5 is suppressed. Not limited to this. When the engine speed becomes equal to or higher than the limit speed RMAX, only one of the suppression of the fuel injection amount to the engine 5 and the suppression of the ignition of the engine 5 may be performed. Further, even if the engine speed becomes equal to or higher than the limit speed RMAX, neither the suppression of the fuel injection amount to the engine 5 nor the suppression of the ignition of the engine 5 may be performed.

(9) In the above embodiment, the drive belt 25 is made of rubber, but the present invention is not limited to this. For example, the drive belt 25 may be made of metal.

The present invention can be used for various work vehicles such as all-terrain vehicles, tractors, and mowers, in addition to the above-mentioned multipurpose vehicles.

5: Engine 16: Belt type continuously variable transmission 22: Input rotating body 24: Output rotating body 25: Drive belt 42: Rotation detection unit 44: Vehicle speed detection unit 45: Engine control unit 47: Notification unit A1: Preliminary value A2: Threshold B1: Preliminary notification B2: Warning notification C: Tolerance range T: Traveling device VMAX: Limit maximum vehicle speed

Claims (4)

A belt having an input rotating body, an output rotating body, the input rotating body, and a drive belt wound around the output rotating body, and continuously shifting the power from the engine to the traveling device. With a continuously variable transmission mechanism
A rotation detector that detects the engine speed and
A vehicle speed detector that detects the vehicle speed of the traveling aircraft,
When the vehicle speed detected by the vehicle speed detection unit is a predetermined vehicle speed and the engine speed detected by the rotation detection unit deviates from a preset allowable range, a warning notification is given to warn the wear of the drive belt. It is equipped with a notification unit ,
The predetermined vehicle speed is a limit maximum vehicle speed preset as a vehicle speed for suppressing the rotation of the engine, and the vehicle speed detected by the vehicle speed detection unit is the limit maximum vehicle speed only when the limit maximum vehicle speed is reached. A work vehicle in which the notification unit gives the warning notification when the engine speed exceeds a predetermined threshold value . The work vehicle according to claim 1 , wherein the threshold value is the engine speed at which the limited maximum vehicle speed is achieved in the belt-type continuously variable transmission mechanism having the drive belt in a predetermined wear state. The work platform according to claim 1 or 2 , wherein the notification unit performs a preliminary notification different from the warning notification when the engine speed exceeds a preliminary value smaller than the threshold value. Claim 1 is configured to suppress the engine speed when the engine speed becomes equal to or higher than the limit speed set based on the threshold value, even if the vehicle speed does not reach the limit maximum vehicle speed. The work vehicle according to any one of 3 to 3 .

Images